Bones and bony structures are susceptible to a variety of weaknesses that can affect their ability to provide support and structure. Weaknesses in bony structures may have many causes, including degenerative diseases, tumors, fractures, and dislocations. By way of example, weaknesses in vertebrae can lead to compression fractures that involve the collapse of one or more vertebrae in the spine. These vertebral compression fractures may be caused by a number of conditions including osteoporosis, trauma, and tumors. Advances in medicine and engineering have provided doctors with a plurality of devices and techniques for alleviating or curing these weaknesses.
One technique for treating vertebral fractures is vertebroplasty. In vertebroplasty, a physician may use a needle to inject filler material (e.g., bone cement) into a fractured vertebral body to stabilize the fracture. Kyphoplasty is another technique for treating vertebra fractures that involves insertion of a balloon into the fractured vertebra to restore the height of the vertebra. The balloon may then be removed followed by injection of filler material into the vertebral body to stabilize the fracture.
A number of different devices have been developed for injection of filler material into fractured vertebrae. For example, syringe-type devices have been used that comprise a plunger and a chamber. The physician manually advances the plunger to eject filler material from the chamber. Drawbacks to syringe-type devices include problems generating the necessary pressure to eject the filler material in certain applications. Additional drawbacks include precisely controlling the volume of filler material ejected from the chamber. Mechanical devices have also been used for the injection of filler material that may include, for example, a housing that supports a cartridge containing bone cement. The mechanical devices further may include a plunger that forces the filler material from the cartridge. The ram may be activated by a trigger mechanism or screwing mechanism, for example.
Thus, there is a need for methods and devices that can be used to deliver bone filler material.